We constructed a phylogeny for 10 minnow species (family Cyprinidae) previously revealed to be members of sister genera with different dietary affinities and used the phylogeny to examine whether the evolution of digestive tract size and physiology is correlated with the evolution of diet in these fishes. We studied a total of 11 taxa: four herbivorous species in the genus Campostoma and six largely carnivorous species in the genus Nocomis, including two populations of Nocomis leptocephalus, the carnivorous Chattahoochee River drainage population and the herbivorous Altamaha River drainage population. Thus, we were able to compare digestive tract size and physiology among sister genera (Campostoma and Nocomis) and among sister taxa (N. leptocephalus Chattahoochee and N. leptocephalus Altamaha) in dietary and phylogenetic contexts. The herbivorous taxa had longer digestive tracts and higher activity of the carbohydrases amylase and laminarinase in their guts, whereas the carnivorous species had higher chitinase activity. Phylogenetic independent-contrast analysis suggested that the evolution of amylase and chitinase activities was correlated with the evolution of diet in these species, whereas trypsin and lipase activities showed no pattern associated with diet or phylogenetic history. Concentrations of short-chain fatty acids were low in all taxa, indicating that these fishes rely largely on endogenous digestive mechanisms to subsist on their respective diets. Subtle differences in tooth shape were observed between species in the two genera. Overall, our results suggest that dietary specialization can be observed on the level of anatomy and physiology of the digestive tracts of fishes but that such differences are most appropriately viewed in comparisons of closely related species with different diets.

External morphological traits diagnostic for valid genera in the Asian catfish families Sisoridae and Erethistidae were identified from publications and the examination of specimens. Diagnoses based on external morphological traits are predicted to significantly facilitate taxonomic revisions in these families. Erethistidae contains six valid genera (Ayarnangra, Caelatoglanis, Conta, Erethistes,       Erethistoides, Pseudolaguvia) and about 25 species. Sisoridae contains 16 valid genera (Bagarius, Euchiloglanis, Exostoma, Gagata, Glaridoglanis, Glyptosternon, Glyptothorax, Gogangra, Myersglanis, Nangra, Oreoglanis, Parachiloglanis, Pareuchiloglanis, Pseudecheneis, Pseudexostoma, Sisor) and about 144 species. Lists of valid species and their distributions are given for each genus.

This study reports five species of Pareuchiloglanis in the Lancangjiang drainage of China, including descriptions of two new species: P. abbreviatus sp. nov., P. gracilicaudata, P. kamengensis, P. myzostoma and P. prolixdorsalis sp. nov. The two new species are distinguished from P. feae, P. poilanei, P. sichuanensis and P. tianquanensis by a shorter adipose-fin base and the adipose-fin base being separated from the caudal fin, differ from P. sinensis, P. macrotrema, P. longicauda and P. rhabdurus by a more restricted gill opening (not reaching the base of the first pectoral-fin element ventrally), and differ from P. songmaensis by an anal-fin ray count of ii-3-4 (vs. ii-8). Pareuchiloglanis abbreviatus is distinguished from congeners by the tip of the dorsal fin reaching the origin of the adipose fin when depressed. Pareuchiloglanis prolixdorsalis is distinguished from P. gongshanensis, P. macropterus and P. kamengensis by lacking a sulcus between the lower lip and the base of the maxillary barbel, and differs from P. anteanalis by the shorter pectoral fin, the pectoral fin not reaching to the origin of pelvic fin. It differs from P. gracilicaudata, P. myzostoma, P. nebulifer and P. robusta by a caudal-fin ray count of 6+7 (vs. 7+8), and differs from P. abbreviatus by the tip of dorsal fin not reaching to the origin of the adipose fin when depressed (vs. reaching). It differs from P. songdaensis by the distance between the origin of the pelvic fin to the base of the anal fin being longer than that to the mouth (vs. equal).

Creteuchiloglanis, new genus, is established for three species previously placed in Pareuchiloglanis (P. gongshanensis, P. kamengensis, and P. macropterus) and two new species described herein. Creteuchiloglanis is distributed in the upper Mekong River (Lancang-Jiang) basin west to the Brahmaputra River basin and is distinguished from Pareuchiloglanis by a unique combination of characteristics involving the form of the connection of the lower lip to the maxillary barbel, premaxillary tooth patches, and the morphology of the dilator, operculi, sternohyoideus, and adductor pelvicalis superficialis muscles. Creteuchiloglanis brachypterus, new species, from the upper Irrawaddy River basin in China, is diagnosed by a unique combination of characteristics involving pectoral-and pelvic-fin length, caudal-peduncle length and depth, pelvic-fin position, caudal-fin length, eye size, body and head depth, and coloration. Creteuchiloglanis longipectoralis, new species, from the upper Mekong River (Lancang-Jiang) basin, is diagnosed by a unique combination of characteristics involving pectoral-and pelvic-fin length, caudal-peduncle length and depth, pelvic-fin position, body and head depth, post-adipose fin distance, number of dorsal-fin rays, and coloration. New diagnoses are provided for previously described congeners C. gongshanensis from the upper Salween River (Nu-Jiang) basin, C. kamengensis from the Brahmaputra basin, and C. macropterus from the upper Irrawaddy River and upper Salween (Nu-Jiang) basins. C HU (1981) resurrected the catfish genus Pareuchiloglanis Pellegrin 1936 for species in the genus Euchiloglanis that lack a posterolateral extension of each premaxillary tooth patch (vs. posterolateral extension present in Euchiloglanis). Seven species and two subspecies were placed in Pareuchiloglanis, including P. poilanei (type species), P. feae feae, P. feae myzostoma, P. kamengensis, P. gracilicaudata, P. gongshanensis, P. macrotrema, and P. sinensis. A morphology-based phylogenetic analysis of glyptosternine catfishes found Pareuchiloglanis to be nonmonophyletic (He, 1995(He, , 1996. Therein, specimens identified as P. feae from Yunnan and P. kamengensis were found to be more closely related to the genera Pseudexostoma and Oreoglanis than to a clade composed of Pareuchiloglanis macrotrema, P. longicauda, and P. myzostoma.A study using mitochondrial cytochrome b and 16S rRNA gene sequences (Guo et al., 2005), and another using mitochondrial genes (cytochrome b and ND4) and one nuclear gene (rag2; Peng et al., 2006), found specimens identified as Pareuchiloglanis kamengensis to be more closely related to species of other genera of glyptosternines than to the other examined species of Pareuchiloglanis. These molecular results corroborate the non-monophyly of Pareuchiloglanis discovered by He's (1995He's ( , 1996 morphological analysis.Nevertheless, recent studies continued to recognize Pareuchiloglanis as defined by Chu (1981) and new species continue to be described in this genus. Thomson and Page (2006) recognized ...